Sometimes reviews like this begin with a choice quote from the show. I tried that, but it didn't work. The lines that stood out were either theological in content or far too lewd. I think we all know which line, in particular, I'm talking about.

So welcome to the series blog for 'The Pillars of the Earth', a £40m German-Canadian adaptation of Labour supporter Ken Follett's bestselling novel. It's a 12th century tale of power, politics and passion, and also, in an unlikely twist, masonry. The throne of England may be up for grabs and innocent people may be burned at the stake, but Prior Philip is having his cathedral done up if it kills him. Fortunately the man he's got in for the job has called himself Tom Builder. He'll go far.

In this weekend's opening double bill, we are informed as to the lie of the land. King Stephen is on the throne, there thanks to an audacious act of poisoning and the backing of the Catholic church. One of their rising men, and by "rising" I mean entirely duplicitous and unflinchingly ruthless, is Bishop Waleran. With constantly glowering features and a jet-black centre-parting that's straight out of vampire school, you know Waleran's disposition just by looking at him.

He's played with obvious relish by Ian McShane, perhaps delighted to get his teeth into a character of Swearengenian proportions. So far Waleran has – so I've inferred at least – killed an heir to the throne, stitched up the good man Bartholomew (the mighty Donald Sutherland who surely doesn't deserve such treatment) and embroiled young Philip (Matthew Macfadyen) in dark conspiracies from which a pious young monk should have steered well clear. In his favour, Philip does at least seem to run a charitable priory – taking in repentant thieves, for example. And the babies they've stolen.

That baby is the son of Tom the Builder (geometrically hunky Rufus Sewell). By fortunate coincidence child and father are both separated and reunited with within the first hour of the drama as Tom first abandons the baby in the woods, regrets the decision, and then turns up at Philips' insisting he can fix up his house of worship only to find his child's kidnapper already there. There are more characters: Tom's lover Ellen who may have been reduced to scavenging in the woods for fungi but knows all about the heir's death at sea; her son, Jack, who is a whizz with the sculpting and has brooding good looks straight out of a Twilight movie; and the Hamleigh family who, as well as a lust for power, have many unresolved sexual issues.

This is a big, high-powered cast, dumped into a grotty, sparsely populated world. The court of King Stephen is not only tatty, it's half-empty, like the upstairs room of a pub on a Tuesday night. The countryside is more like an uncultivated wilderness; wolves still stalk the land (100 years later Edward I began a campaign to eradicate them and largely succeeded). The England of Pillars of the Earth is a young country, and the sense of opportunity (as well as anarchy) is in the air.

It's an unusual backdrop for a drama and there is obviously room for some big themes to be explored. Pillars of the Earth has been described as Trojan Horse TV – in that the audience is treated to a history lesson under the guise of a dramatic romp. I'm not, as yet, overly convinced by the historical elements, and I would like to know more about life as it was lived, particularly religious life. We are in a religious country where the most tangible power is held by the church but are yet to see much of how religion impacts on the way people think.

We know Tom the Builder sees his cathedral as an anteroom, as something "halfway to heaven"; his work somehow enables our understanding of the divine. We also see Waleran immolating himself in the hope of suppressing sexual desire. But in the main – and especially with Macfadyen's Philip – we don't get much of a sense of the love and fear of God as motivation.

While the first half of this omnibus feels a bit contrived – coinciding births and deaths, moments of peaceful enjoyment interrupted by brutal fighting and a scenario bringing the central characters together on the stage rather quickly – the second half (or episode) is more leisurely in its pacing and offered fewer revelations. We see Tom begin his work on the cathedral and controversy engulf Ellen, but more energy is spent on defining the characters and their relationships. Central, I think, is the unseemly tug Tom feels between his real son, a not-exactly quick-witted coward, and his adoptive one, Jack, almost literally a chip off the old block. More intriguing though will be the central female characters, Bartholomew's daughter Aliena and the insurgent Queen Maud.

So what did you make of it all? Is Waleran going to be up there with Al Swearengen, Teddy Bass and, er, Lovejoy in McShane's hall of fame? Will the central device of Cathedral construction keep you hooked? And what is it with all the beards? Do share your thoughts below and join me again next week for the next installment.